1. The graphite refill used is pencil is made of element called __________
2. The smallest unit of an element is __________
3. __________ can be formed by the same or different kinds of atoms.
4. The most abundant type of atom is the universe is __________
5._________ is a substance that is made up of three oxygen atoms chemically combined.
6. A molecule containing three atoms is called a __________ molecule
7. A molecule which contains only one atom is called __________ molecule
8. An atom of Oxygen (O) and two atoms of hydrogen (H.) combine to form a molecule of
9. Matter is its simplest form is called __________
10. __________ is the first scientist who used the term element.
11. The atomic number of an atom is __________
12. There are two electrons in the outermost orbit of the magnesium atom. Hence, the valency of magnesium _____
13. The atomic number of an element is 9, it has 10 neutrons. Find the element from the periodic table. What will be its mass number?
14. ________ is made up of two or more atoms.
15. The average diameter of an atom is ________
16. Whose theory does not propose anything about the positive and negative charges of an atoms.
17. _______ is the smallest unit used to measure small lengths.
18. One Nano metre is equal to ________
19. Who discovered the existence of the negatively charged particles is an atom?
20. J.J Thomson’s atom model is also called as ________
21. _________ of the following are endothermic changes.
22. The chemical change is _______
23. The change of state of a substance from solid to liquid and liquid to gas is ____________
24. Keeping a stone in sunlight for few hours is ____________
25. Which of the following is not a physical change?
26. Cut vegetables turn brown when exposed to air, this is due to ____________
27. Which gas is produced when vinegar reacts with baking soda?
28. The simplest method of preventing rusting of iron is to coat it with oil, grease or paint. The reason being ____________
29. Large crystals of pure substances can be obtained from their solutions by the process of ____________
30. Beating an egg to make a cake is a ____________
31. The first man-made fibre is ________
32. A synthetic fibre which has similar properties to wool is ________
33. A good application of plastic is the use of ________
34. ________ is non-biodegradable material.
35. Which of the following is the strongest?
36. PET is the acronym for ________
37. Which is a thermosetting plastic?
38. The material similar to silk in appearance is.
39. The fibres such as rayon, nylon, polyester are obtained from
40. Which of the following is found in sanitary products?
41. A drug effective in the treatment of pneumonia, and bronchitis, is ______
43. Which of the following conditions is not necessary for combustion?
44. During diarrhoea the intestine is still able to absorb molecules.
45. Our stomach naturally produce to help digest and breakdown food.
46. _______ are substances applied to the exterior of a body that kill microbes.
47. All combustion reactions are .
48. Any reaction that involves reaction with oxygen is called__________ reaction.
49. Which is the luminous part of the plame?
50. Antacids are actually .